1. Field of the Invention
The present invention relates to a method for forming a very durable, waterproof and unevenly textured coating film on the wall surfaces of structures.
2. Background Information
It is known that compositions which consist of an acrylic resin or urethane resin aqueous emulsion, inorganic filler and short fiber are useful as coating materials which can be sprayed and cured on the interior and exterior wall surfaces of buildings to form waterproof coating films while simultaneously providing an uneven texture (for example, Jap. Pat. Appln. Laid Open Nos. 50-13426 [13,426/75], 50-65533 [65,533/75], Jap. Pat. Publication No. 54-32651 [32,651/79], and Jap. Pat. Appln. Laid Open No. 50-133235 [133,235/75]).
U.S. Pat. No. 4,496,687, issued Jan. 29, 1985, teaches a siloxane containing emulsion which can give an elastomer upon removal of water. The composition is stated as useful as a coating composition, fiber treating agent, binder for inorganic material and the like.
U.S. Pat. No. 4,572,917, issued Feb. 25, 1986, teaches a method of manufacturing a fiber reinforced silicone foam. An aqueous silicone emulsion is combined with inorganic fibers and frothed.
Silicone resins which cure at room temperature are taught in U.S. Pat. No. 3,499,870, issued Mar. 10, 1970. A hydroxyl containing methylphenylpolysiloxane resin, a hydroxylated dimethylpolysiloxane fluid, methyltriacetoxysilane and tin catalyst are combined to give the composition.
Room temperature curing resins are also taught in U.S. Pat. No. 4,267,297, issued May 12, 1981. An improved resin contains hydroxylated organopolysiloxane, an alkoxylated organopolysiloxane, an alkoxysilane, an aminoalkylalkoxysilane, and a tin catalyst.
However, while coating films can be formed by the curing of coating materials composed of acrylic resin or urethane resin, the weather resistance of such coating films is inadequate, and their properties are gradually degraded by long-term exposure to ultraviolet radiation and their elasticity is lost as a consequence. As a result, the cured coating film will crack, which spoils its aesthetics as a coating material. In particular, rain will penetrate through the cracks to reach the interior of the building, thus raising the problem of rain leakage. Also, these types of coating films have very low elongations at low temperatures, and so cannot be used in regions of cold.
The inventors carried out investigations in order to eliminate the aforesaid problems, and the present invention was developed as a consequence.